NEW YORK (AP) - JetBlue thinks it's found the right combination for growth in the airline industry: The Red Sox and white sand beaches.

The airline said yesterday it will continue its rapid expansion in Boston and the Caribbean while reducing service in other places.

It also said again that it will fly solo, instead of tying up with another airline.

In Boston, JetBlue is looking for more business travelers who will pay higher fares. In the Caribbean, it's appealing to the customers that other airlines have pulled away from: vacationers to the Dominican Republic, Jamaica and Barbados.

JetBlue plans to add 25 new flights from Boston by next year, bringing its total to 100. It recently announced its 17th Caribbean destination - Turks and Caicos. The airline will start flying there next May.

More flights and higher fares quadrupled JetBlue's third-quarter earnings. Income in that quarter alone topped what it made all of last year.

The company earned $59 million, or 18 cents per share in the three months ended September 30 - usually the best quarter of the year because it includes the busy summer travel season. A year ago, JetBlue earned $15 million, or five cents per share.

Although discounters like JetBlue and Southwest fared better than Delta, United and American in 2008 and 2009, they still felt the impact of slumping travel demand. Now, all US airlines are posting their best third-quarter results in several years as more passengers return to the skies.

JetBlue said revenue rose 21 percent to $1.03 billion. It flew nine percent more passengers this summer than a year earlier. An average one-way fare cost about $142 in the third quarter, 11.6 percent higher than last year. JetBlue said its efforts to get more higher-paying business travelers are paying off, but it wants more.

That goal has become more important since its two main low-cost rivals, Southwest and AirTran, announced plans to combine.

JetBlue, based in the New York City borough of Queens, expects to increase its capacity - the number of available seats - by eight to 10 percent in the fourth quarter as it continues to deploy new planes in its growing Boston and Caribbean markets. At the same time, it plans to delay some plane deliveries to control its overall growth.